Treatment of Spontaneous Subarachnoid Hemorrhage: A 20-year National Inpatient Sample Review

2024 · doi:10.1101/2024.05.01.24306726
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This retrospective study used the National Inpatient Sample to examine national trends from 2001–2020 in hospitalizations for spontaneous subarachnoid hemorrhage, focusing on admissions that underwent microsurgical or endovascular treatment to secure a ruptured aneurysm. The incidence of spontaneous SAH hospitalizations decreased over time, and among surgically treated aneurysmal SAH cases the patient mix shifted toward older age and more severe illness, while use of microsurgery declined substantially in favor of endovascular surgery. Hospital mortality remained stable at about 13% across the study period despite increasing severity indices, and adjusted analyses showed lower odds of hospital mortality in the final epoch versus the first. This paper does not explicitly discuss endometriosis or adenomyosis; it was included in the corpus via a keyword match in the upstream search index.

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Abstract

Background Aneurysmal subarachnoid hemorrhage is a major source of morbidity and mortality, and its management has undergone foundational changes over the last 2 decades. We reviewed the National Inpatient Sample (NIS) to outline the changes in severity of illness, surgical management, and patient outcomes over time. Methods A retrospective cohort of admissions for spontaneous subarachnoid hemorrhage (SAH) in the NIS from 2001-2020 was reviewed, including those that underwent microsurgical or endovascular surgery to secure a ruptured aneurysm. National incidence was calculated, and multivariable regression was used to identify changes in incidence and outcome through time, segmented by epoch. Results Review of the NIS identified 450,723 SAH patients, of which 182,151 underwent surgical aneurysm treatment. The incidence of spontaneous SAH fell −0.127 per 100,000 person-years each year [95%CI: −0.164, −0.0887]). Among patients surgically treated for aneurysmal SAH, the proportion of patients <50 years old fell from 40% to 30% between first and final epochs, and the proportion of those in the lowest stroke scale category, roughly equivalent to Hunt & Hess grade 1 or 2, fell from 68% to 49%. The proportion treated by microsurgery fell from 70% to 23% in favor of endovascular surgery. Hospital mortality among these treated cases was stable at 13% throughout the study period despite increasing illness severity indices. After adjustment, there was a 41% reduction of odds of hospital mortality in the final epoch compared with the first. Conclusions The incidence of hospitalization for spontaneous SAH fell between 2001 and 2020. Patients undergoing surgery to secure an aneurysm were more severely ill through time yet experienced a stable hospital mortality rate.
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Abstract

Background Aneurysmal subarachnoid hemorrhage is a major source of morbidity and mortality, and its management has undergone foundational changes over the last 2 decades. We reviewed the National Inpatient Sample (NIS) to outline the changes in severity of illness, surgical management, and patient outcomes over time.

Methods

A retrospective cohort of admissions for spontaneous subarachnoid hemorrhage (SAH) in the NIS from 2001-2020 was reviewed, including those that underwent microsurgical or endovascular surgery to secure a ruptured aneurysm. National incidence was calculated, and multivariable regression was used to identify changes in incidence and outcome through time, segmented by epoch.

Results

Review of the NIS identified 450,723 SAH patients, of which 182,151 underwent surgical aneurysm treatment. The incidence of spontaneous SAH fell −0.127 per 100,000 person-years each year [95%CI: −0.164, −0.0887]). Among patients surgically treated for aneurysmal SAH, the proportion of patients <50 years old fell from 40% to 30% between first and final epochs, and the proportion of those in the lowest stroke scale category, roughly equivalent to Hunt & Hess grade 1 or 2, fell from 68% to 49%. The proportion treated by microsurgery fell from 70% to 23% in favor of endovascular surgery. Hospital mortality among these treated cases was stable at 13% throughout the study period despite increasing illness severity indices. After adjustment, there was a 41% reduction of odds of hospital mortality in the final epoch compared with the first.

Conclusions

The incidence of hospitalization for spontaneous SAH fell between 2001 and 2020. Patients undergoing surgery to secure an aneurysm were more severely ill through time yet experienced a stable hospital mortality rate. Competing Interest Statement The authors have declared no competing interest. Funding Statement The authors received no external funding to support this work. Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: Lifespan IRB I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes Data Availability Research data and statistical code will be made available upon request.

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